The human brain produces electrical brain waves at frequencies ranging from 0 to 64 Hertz (Hz). Within this range are delta waves from 0 to 3 Hz, theta waves from 3 to 8 Hz, alpha waves from 8 to 13 Hz, and beta waves from 13 to 64 Hz. These brain waves are usually present at any given time but in varying magnitudes depending on an individual's thought processes. Beta levels dominate during the alert awakened state. Alpha levels rise and beta levels fall in the light sleep state. Theta levels increase while alpha and beta levels decrease during the deep sleep state. Delta levels rise during a deep-deep sleep state.
It is known that an increase in physiological stress is manifested by low levels of alpha and theta brain waves. An increase in theta frequency levels produce the best physiological stress reduction results, yet they are the most difficult for individuals consciously to produce. While it has been found that an increase in theta frequency levels correspondingly increases alpha frequency levels, the reverse is not true. The more readily increased alpha brain waves do not correspondingly increase theta brain wave levels.
Current techniques used to reduce psychological stress are essentially limited to conscious mental efforts. This is sometimes achievable through pure meditation and sometimes not. Such technique is thus often unreliable. Physiological stress reduction can also be achieved by mental exercises in association with electronic biofeedback instruments that inform individuals of their success or failure in controlling brain wave frequencies, and which assist in altering brain wave frequencies. These bio-feedback instruments typically employ sensors that are attached to the individual's skull and which are electrically coupled with analytic and display apparatuses. Since the individual is physically attached to the instrument, limitations in movement exist which can inhibit the ability of the individual to increase his or her alpha and theta brain wave frequencies and to maintain such increases for a sufficiently period of time to achieve therapeutic results.
Thus, there remains a need for a method of reducing physiological stress that does not require conscious mental effort by individuals and which does not require the attachment of devices to the persons. Accordingly, it is to the provision of such physiological stress that the present invention is primarily directed.